Back to the original question, is anyone running Arc8's with ST coilovers? I had the one response saying they hit the springs. Was it the springs or the adjusting collar. How low was the set up. I don't intend on dropping the car much. I just want to better the set up.

Back to the original question, is anyone running Arc8's with ST coilovers? I had the one response saying they hit the springs. Was it the springs or the adjusting collar. How low was the set up. I don't intend on dropping the car much. I just want to better the set up.

As mentioned previously the limitation with ST coilovers is that it uses a progressive spring that is cone shaped which creates for much less wheel and tire clearance in front. If you raise the spring perch or "adjusting collar" above the wheel and tire then you should be fine with clearances. As a solution to the progressive springs we always recommend a linear spring conversion using 6 inch hyperco, swift, or eibach springs and camber plates to create the most room possible in front as we can.

ST coilovers as shipped with progressive springs can be run with 18x8.5" ET45 ARC-8's and 235/40/18 tires as long as you make sure the spring perch or "adjusting collar" is above the wheel and tire.

Not usually, unless the coilover was designed to run the lower perch below oem perch height. You should be okay as long as the perch is above the wheel and tire and with most high quality coilover, that is the case. Just have to watch out for those "other" ones out there.

Someone mentioned the use of a cone shaped spring on the ST and KW V series, that really has nothing to do with tire/wheel clearance unless it wasn't designed properly and the lower perch is allow to invade the space not previously occupied.

Someone mentioned the use of a cone shaped spring on the ST and KW V series, that really has nothing to do with tire/wheel clearance unless it wasn't designed properly and the lower perch is allow to invade the space not previously occupied.

I will clarify Joe's statement above. The spring length of all the KW cone shaped springs is long so they push the lower spring perch down and result in the need for 10-15mm spacer in many applications we've seen to clear what previously worked. This is because you're no longer clearing the strut tube anymore, you're clearing the spring since it is beside the tire instead of above it.

Harold is correct, the cone shape is not what causes the interference on it's own. To be clear it is the length that causes this problem. Linear cylindrical race springs that are too long would cause just as much interference. But to be clear, there are no cone shaped springs out there for BMW applications that are short. They are all long, and so it is a safe generalization to say that the KW cone shaped springs (springs that go from 61mm diameter at the bottom to OEM spring diameter at the top) will be long and will cause suspension side interfeerance on wide/tight fitments vs. a setup that keeps the lower spring perch above the tire.

Joe stated that one could adjust the lower perch above the tire on those kits, but in reality this is not possible. This would effectively set the ride height above stock height most likely, as the lower perch is usually 1-2" too low to clear the tire.

The 18x8.5" et45 wheel was designed to clear the factory suspension up front spacer free depending on the tire used. If an aftermarket suspension is used that has a wider strut body, then a thin 3-5mm spacer will be needed because of that variable change. If a wide tire is used, the same would be true. Example, a 245/35/18 Hoosier R6 needs a 3mm spacer to clear a koni based coilover like a TCK kit.

The coilovers to really avoid on the 1 series are the ones that use a threaded sleeve on the entire strut body to adjust the ride height instead of the spring perch. The body will be significantly wider, and they tend to use an inverted strut which usually requires the use of a long spring. Those will not play well with wide wheels unless thick spacers are used, and we all know how little room the 1 series has to push wheels out towards the fender.

Joe stated that one could adjust the lower perch above the tire on those kits, but in reality this is not possible. This would effectively set the ride height above stock height most likely, as the lower perch is usually 1-2" too low to clear the tire.

this does not agree with my experience. i'm using KW V1 coilovers (which use the conical front spring, possibly the exact same spring as the ST?), and at my height, which is about an inch lower than stock, the spring perch and spring are still above the tire, so when using reasonably-sized tires, no spacer is required with my et45 arc-8 front wheels. i have to use a spacer to get the 255/35 star spec to work, but that's just to clear the strut body, not the perch or the spring.

On a sort of related note, does installing coilovers (KW in my case, ST isn't available in the UK although I believe KW make ST) mean that you need to run spacers with any wheels using the stock offset (inc stock 261/264's)?

If you were to install an aftermarket wheel such is VMR's with 45mm offsets all round, would that prevent inner rubbing?

I have a set of APEX Arc8 (18x8.5in et 45) that I use with 235/40 NT-01s (square) on the track. I just purchased a set of JRZ RS1s, and am planning on purchasing springs (6 in front/9in rear?).

Keeping in mind that I run my vorshlag plates around -2.5 camber for both street and track, will I have any problems with fitment/rubbing up front? Will I need spacers? Just not sure how much of a spacer one could use with these wheels in the front, since they are already pretty wide...

I have a set of APEX Arc8 (18x8.5in et 45) that I use with 235/40 NT-01s (square) on the track. I just purchased a set of JRZ RS1s, and am planning on purchasing springs (6 in front/9in rear?).

Keeping in mind that I run my vorshlag plates around -2.5 camber for both street and track, will I have any problems with fitment/rubbing up front? Will I need spacers? Just not sure how much of a spacer one could use with these wheels in the front, since they are already pretty wide...

-2.5 degrees of camber in the front will definitely provide adequate room for the fender side for your 235/40/18 Nitto NT01's. As long as you pay attention to the location of the spring perch on the JRZ's relative to the wheel and tire and make sure that the spring perch is above the wheel and tire than you should not have problems with rubbing, especially if you are using a 6" linear race spring. We have had a couple customers who's coilovers were spec'd with 7" front springs and they ran into rubbing issues because the spring was too long. At most you may need a 3-5mm front wheel spacer to clear but you should be ok without one and even if you do your camber plates will allow for adequate fender clearance.